Abstract
Raman scattering was performed on Gex Si1-x (x=0.54 or 0.28) alloy nanocrystals embedded in amorphous Si oxide. An asymmetric, depolarized, and size-dependent low-frequency Raman peak was observed and identified as the superposition of two surface acoustic vibration modes of the alloy nanocrystals. The current theoretical models can be used to explain the mode frequencies but not the dampings observed experimentally. Based on energy-dispersive x-ray microanalysis and density-functional-theory total energy optimization of structures, a modified core-shell-matrix model in which the effects of neighboring nanocrystals in the matrix are taken into account is in good agreement with experiments. This work provides good insight into the frequencies and dampings of acoustic vibrations of the nanocrystals embedded in the matrix. © 2008 The American Physical Society.
| Original language | English |
|---|---|
| Article number | 165319 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 78 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - 22 Oct 2008 |
Publisher's Copyright Statement
- COPYRIGHT TERMS OF DEPOSITED FINAL PUBLISHED VERSION FILE: Wu, X. L., Xiong, S. J., Yang, Y. M., Gong, J. F., Chen, H. T., Zhu, J., Shen, J. C., & Chu, P. K. (2008). Nanocrystal-induced line narrowing of surface acoustic phonons in the Raman spectra of embedded GexSi1-x alloy nanocrystals. Physical Review B - Condensed Matter and Materials Physics, 78(16), [165319]. https://doi.org/10.1103/PhysRevB.78.165319. The copyright of this article is owned by American Physical Society.